The equipping of combustion engines with mechanisms that make it possible to vary the opening and closing of the valves both with regard the length of the period of opening and its position in relation to the crankshaft angle, and that also make it possible to vary the lift height of the valves is already known. A mechanism can be arranged to vary the valve timing and the lift heights for all the inlet valves simultaneously, while another can be arranged to vary the valve timing and the lift heights for all the exhaust valves simultaneously. Recently, however, mechanisms have been developed that make it possible to regulate each valve individually with regard to valve timing and lift height. By continually regulating the valve timing and the valve lift height to suit the engine's operating conditions while the vehicle is being driven, better efficiency, increased life of components, better performance (for example with regard to emissions), better response (power performance), and better handling can be attained than for a comparable engine with non-variable valve timing and/or valve lift heights.
It is common to all such previously-known regulation that the adjustment of the valves is instantaneous and internal in the engine, which means that it can not predict and take into account future transients in the engine's operating condition. Such transients are, for example, gear changes in the vehicle's gearbox or in association with a general increase/reduction in torque or in association with connection/disconnection of engine braking when going downhill. Even though the actual valve adjustment for matching a new operating condition can be carried out very quickly with modern equipment, the large volumes, particularly in the pipe systems of turbocharged engines on the inlet side, and the inertia in the turbo unit have meant that, to date, delays in the adjustment to the operating condition have not been able to be avoided. For example, delays of up to three to four seconds have not been uncommon, which has a negative effect on the engine's emissions, response, efficiency and handling.